A new stereoselective synthesis of phosphiranes

Article abstract of DOI:10.1021/jo9608533

The synthesis of phosphiranes from primary phosphines and diol ditosylates was found to be stereoselective, and chiral phosphiranes were prepared from optically pure diols. The four optical isomers of 1-mesityl-2,3-dimethylphosphirane, (2S,3S)-(+)-3, (2R,3R)-(-)-4, anti-cis-(meso)-5, and syn-cis-(meso)-6, were all synthesized from mesitylphosphine and the corresponding diol ditosylates. Compound 6 was unstable, but compounds 3, 4, and 5 were all isolated in pure form. Their structure assignments were based on the NMR coupling constants J_P-H and J_P-C. The phosphiranes were transformed into tungsten pentacarbonyl complexes. Tungsten tetracarbonyl-triphenylphosphine complexes (22, 23, 24) of compounds 3, 4, and 5 were synthesized in high yields by the reaction of the phosphiranes and W(CO)₄(PPh₃)(THF). The absolute stereochemistry of the phosphiranes 3, 4, and 5 was determined by X-ray crystal structure analysis of compounds 22, 23, and 24. Stereochemical effects on NMR coupling constants and mass spectra of the phosphiranes are discussed.

Full text of DOI:10.1021/jo9608533

7
702
J . Org. Chem. 1996, 61, 7702-7710
A New Ster eoselective Syn th esis of P h osp h ir a n es
†
Xinhua Li, Kerry D. Robinson, and Peter P. Gaspar*
Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899
Received May 8, 1996X
The synthesis of phosphiranes from primary phosphines and diol ditosylates was found to be
stereoselective, and chiral phosphiranes were prepared from optically pure diols. The four optical
isomers of 1-mesityl-2,3-dimethylphosphirane, (2S,3S)-(+)-3, (2R,3R)-(-)-4, anti-cis-(meso)-5, and
syn-cis-(meso)-6, were all synthesized from mesitylphosphine and the corresponding diol ditosylates.
Compound 6 was unstable, but compounds 3, 4, and 5 were all isolated in pure form. Their structure
assignments were based on the NMR coupling constants J P-H and J P-C. The phosphiranes were
transformed into tungsten pentacarbonyl complexes. Tungsten tetracarbonyl-triphenylphosphine
complexes (22, 23, 24) of compounds 3, 4, and 5 were synthesized in high yields by the reaction of
4 3
the phosphiranes and W(CO) (PPh )(THF). The absolute stereochemistry of the phosphiranes 3,
4
, and 5 was determined by X-ray crystal structure analysis of compounds 22, 23, and 24.
Stereochemical effects on NMR coupling constants and mass spectra of the phosphiranes are
discussed.
In tr od u ction
The chemistry of phosphiranes is underdeveloped by
Sch em e 1
Sch em e 2
comparison with that of their oxygen, nitrogen, and sulfur
counterparts.1 Evidence from this laboratory indicates
that phosphiranes are good precursors of phosphinidenes
R-P, molecules containing monovalent phosphorus at-
oms.2 The small cone angle at the phosphorus atom of
phosphiranes suggests that they could act as ligands that
confer interesting properties on metal complexes. Indeed
Marinetti, Ricard, and Mathey have employed the “phos-
pha-Wittig” reaction to synthesize phosphirane-metal
complexes from oxiranes,4 including optically active
examples from which the first chiral phosphiranes were
liberated.5 Chiral phosphiranes or bisphosphiranes are
expected to be useful as ligands in asymmetric catalysis,
since the chiral ring carbons would lie very close to tightly
complexed phosphorus centers.6 Preliminary results
from the Mathey group on hydrogenation with chiral
phosphirane-rhodium complexes have been published.5
,3
phiranes, based on the addition of terminal metal phos-
phinidene complexes to alkenes9 and the “phospha-
Wittig” reaction of phosphorylphosphine complexes with
4,5
oxiranes, are powerful and of considerable interest, but
the sequences, including a final decomplexation of the
phosphirane from a transition metal, are lengthy, ardu-
ous, and expensive.
By the methods reported here, gram quantities of pure
chiral phosphiranes can be easily obtained. We have
found the synthetic approach based on the reaction of a
metal phosphide and a diol ditosylate reported by Oshika-
wa and Yamashita to be very attractive.10 Its simplicity
and directness held promise for practical synthetic utility.
After modification of the procedure by reversing the order
of addition, this method worked well in the synthesis of
1-mesitylphosphirane 1 and 1-supermesitylphosphirane
To assist in the study of the properties of chiral
phosphiranes, a new, efficient, stereoselective method for
the synthesis of phosphiranes has been developed, and
representative examples are described here.
When phosphiranes were first prepared by Wagner and
his co-workers in 1963, their synthesis was based on the
reaction of 1,2-dichloroalkanes and sodium monophos-
7
2
phide in liquid ammonia (Scheme 1). Several other
2. If both displacement steps shown in Scheme 2 are
synthetic methods have been reported, but none is
efficient and general.8 Mathey’s approaches to phos-
(8) Baudler, M.; Germeshausen, J . Chem. Ber. 1985, 118, 4285.
Mercier, F.; Deschamps, B.; Mathey, F. J . Am. Chem. Soc. 1989, 111,
9
098. Katz, T. J .; Nicholson, C. R.; Reilly, C. A. J . Am. Chem. Soc.
*
Telephone (314) 935 6568; FAX (314) 935 4481; e-mail GASPAR@
1966, 88, 3832. Turnblom, E. W.; Katz, T. J . J . Am. Chem. Soc. 1973,
95, 4292. Markel, G.; Alig, B. Tetrahedron Lett. 1982, 23, 4915.
Richter, W. J . Chem. Ber. 1985, 118, 97. Quin, L. D.; Yao, E.-Y.;
Szewczyk, J . Tetrahedron Lett. 1987, 28, 1077. Richter, W. J . Angew.
Chem., Int. Ed. Engl. 1982, 21, 292; Chem. Ber. 1983, 116, 3293.
Niecke, E.; Schoeller, W. W.; Wildbredt, D.-A. Angew. Chem., Int. Ed.
Engl. 1981, 20, 131. Niecke, E.; Leuer, M.; Wildbredt, d. A.; Schoeller,
W. W. J . Chem. Soc., Chem. Commun. 1983, 1171. Markel, G.; Holzl,
W.; Trotsch-Schaller, I. Tetrahedron Lett. 1987, 28, 2693. Schnurr,
W.; Regitz, M. Z. Naturforsch 1988, 43B, 1285; Tetrahedron Lett. 1989,
30, 3951. Niecke, E.; Leuer, M.; Nieger, M. Chem. Ber. 1989, 122, 453.
Yoshifuji, M.; Toyota, K.; Inamoto, N. Chem. Lett. 1985, 441.
(9) Mathey, F. Angew. Chem., Int. Ed. Engl. 1987, 14, 275. In
Multiple Bonds and Low Coordination in Phosphorus Chemistry;
Regitz, M., Scherer, O. J ., Eds.; Thieme: Stuttgurt, Germany, 1990.
Marinetti, A.; Mathey, F.; Fischer, J .; Mitscher, A. J . Chem. Soc., Chem.
Commun. 1982, 667. Marinetti, A.; Mathey, F. Tetrahedron 1989, 45,
309.
WUCHEM.WUSTL.EDU.
†
Current address: Department of Chemistry, Harvard University,
1
2 Oxford Stree, Cambridge, Massachusetts 02138.
X
Abstract published in Advance ACS Abstracts, September 15, 1996.
(
1) Mathey, F. Chem. Rev. 1990, 90, 997.
(2) Li, X.; Lei, D.; Chiang, M. Y.; Gaspar, P. P. J . Am. Chem. Soc.
1
992, 114, 8526.
3) Li, X.; Weissman, S. I.; Lin, T.-S.; Gaspar, P. P.; Cowley, A. H.;
Smirnov, A. I. J . Am. Chem. Soc. 1994, 116, 7899.
(
(
(
4) Marinetti, A.; Ricard, L.; Mathey, F. Synthesis 1992, 157.
5) Marinetti, A.; Mathey, F.; Ricard, L. Organometallics 1993, 12,
1
4
207.
(6) Nugent, W. A.; Rajanbabu, T. V.; Burk, M. J . Science 1993, 259,
Abstr. 1963, 59, 10124; Chem. Abstr. 1964, 60, 559. Wagner, R. I.;
Freeman, L. V. D.; Goldwhite, H.; Rowsell, D. G. J . Am. Chem. Soc.
1
967, 89, 1102.
(10) Oshikawa, T.; Yamashita, M. Synthesis 1985, 290.
S0022-3263(96)00853-5 CCC: $12.00 © 1996 American Chemical Society

Stereoselective Synthesis of Phosphiranes
J . Org. Chem., Vol. 61, No. 22, 1996 7703
Sch em e 3
S
N
2 reactions, it is clear that one should be able to make
was of a similar procedure employing ethylene glycol
bismesylate.12 A recent synthesis of 1-phenylphosphirane
(7) from dilithium phenylphosphide and 1,2-dichloroeth-
phosphiranes stereoselectively, since the configurations
of both chiral carbon centers of the diol ditosylate should
be inverted.
1
3
ane in THF was reported to give a 21% yield.
The generality of this simple synthetic sequence has
been demonstrated by the synthesis of several phos-
phiranes presented below. Its usefulness in the stereo-
selective synthesis of phosphiranes is clear from the
synthesis of four stereoisomers (3-6) of 2,3-dimethyl-1-
mesitylphosphirane, employed as a model system. The
assignment of relative stereochemistry by NMR and the
determination of the absolute stereochemistry of the
phosphiranes by X-ray diffraction of their tungsten
complexes are discussed below.
With the present procedure, 1-phenylphosphirane (7)
was synthesized in 68% yield and easily purified by
vacuum distillation. Low temperatures are not required,
and the procedure should be useful on a larger scale.
A mixture of syn-1-mesityl-2-propylphosphirane (8) and
anti-1-mesityl-2-propylphosphirane (9) was synthesized
in an isolated yield of 24%. Pure anti isomer 9 was
separated by preparative GC, and the less stable syn
isomer 8 was isolated as a 70:30 mixture with 9. The
syn-isomer 8 was recognized from the large coupling of
the phosphorus to the two anti ring protons (J P-H ) 17.5
Hz).
Resu lts a n d Discu ssion
Ster eoch em istr y a n d Cou p lin g Con sta n ts. The
large inversion barrier for the phosphorus (calculated to
be 30-80 kcal/mol)14 leads to the persistence of phos-
phirane diastereomers in which substituents on the ring
carbons are either syn or anti to the substituent at
phosphorus. Previous studies indicated that for substit-
uents on the ring carbon atoms, such as hydrogen, alkyl,
or silyl groups, a large coupling constant (J P-H, J P-C, or
Syn th esis of P h osp h ir a n es by Rea ction of P r i-
m a r y P h osp h in es a n d Diol Ditosyla tes (Sch em e 3).
We reported previously the synthesis of 1-mesitylphos-
phirane 1 and 1-supermesitylphosphirane 2 by our
2
modification of the Oshikawa-Yamashita procedure. A
freshly prepared THF solution of monolithium phosphide
is added dropwise to a solution of diol distosylate. After
the initial displacement of tosylate is complete, a second
equivalent of n-BuLi is added to metallate the remaining
P-H bond and induce cyclization by a second, intramo-
lecular displacement of tosylate. Each stage can be
monitored by 3 P NMR, and if the reaction is found to be
incomplete, a slight excess of n-BuLi is added.
J
P-Si) will be observed if the substituent is syn to the lone
pair at phosphorus (anti to the P-substituent). If the
substituent is anti to the lone pair, the coupling constant
1
15
will be very small or not observable.
shown in Scheme 4.
Examples are
A variety of phosphiranes is made available via this
procedure, limited only by the availability of the corre-
sponding primary phosphines and by the requirement
that the structures of the primary phosphine and the 1,2-
ditosylate are such that substitution occurs rather than
elimination.
These generalizations facilitated the characterization
of the various diastereomers synthesized in this inves-
(
(
12) Denney, D. B.; Shih, L. S. J . Am. Chem. Soc. 1974, 96, 317.
13) Kang, Y. B.; Pabel, M.; Willis, A. C.; Wild, S. B. J . Chem. Soc.,
Chem. Commun. 1994, 475.
14) Bragin, J .; Dennis, L. W. J . Mol. Struct. 1973, 18, 75. Peterson,
(
The first synthesis reported of 1-phenylphosphirane (7)
was by reaction of monosodium phenylphosphide with
H., J r.; Brisotti, R. L., J r. J . Am. Chem. Soc. 1971, 93, 346. Rauk, A.;
Andose, J . D.; Frick, W. G.; Taug, R.; Mislow, K. J . Am. Chem. Soc.
1971, 93, 6507.
1
,2-dichloroethane in liquid ammonia,11 and a later report
(15) Albrand, J . P.; Gagnaire, D.; Martin, L.; Robert, J . B. Bull. Soc.
Chim. Fr. 1969, 40. M a¨ rkl, G.; H o¨ lzl, W.; Tr o¨ tsch-Schaller, I.
Tetrahedron Lett. 1987, 28, 2693. Schnurr, W.; Regitz, M. Z. Natur-
forsch 1988, 43B, 1285; Tetrahedron Lett. 1989, 30, 3951.
(
11) Chan, S.; Goldwhite, H.; Keyzer, H.; Rowsell, D. G.; Tang, R.
Tetrahedron 1969, 25, 1097.

7
704 J . Org. Chem., Vol. 61, No. 22, 1996
Li et al.
Sch em e 4
of 1-mesityl-2,3-dimethylphosphirane (Scheme 5), each
with a distinct 31P NMR chemical shift. The product
mixture (ratio (3 + 4):5:6 ca. 1:1:1) was isolated in 60%
combined yield. The stereochemistries of these isomers
were assigned from their proton-coupled P NMR spec-
tra. The observation of distinct 31P chemical shifts for
the three diastereomers facilitated the examination of the
stereochemistry of phosphirane formation.
3
1
When a racemic mixture of (()-2,3-butanediol ditosy-
late was reacted with phenylphosphide, racemic trans-
(
6
()-2,3-dimethyl-1-phenylphosphirane (13, 14) (Scheme
tigation. The assignments were confirmed by X-ray
crystal structure analysis of the corresponding metal
complexes.
) was obtained in 90% yield. Since none of the cis isomer
3
1
was detected by P NMR even before purification, the
stereoselectivity appears to be >98%. The stereochem-
istry of this compound was assigned on the basis of
characteristic P-H and P-C coupling patterns in the
NMR spectra. The methyl group anti to the phenyl group
has larger coupling constants with phosphorus (J P-H
1
coupling constants with phosphorus (J P-H ) 7.4 Hz, J P-C
) 0 Hz).
Syn th esis of Oth er P h osp h ir a n es. Phosphiranes
with long chain alkyl groups as substituents on carbon
can be synthesized as well. A mixture of 1-mesityl-2-n-
tetradecylphosphiranes (syn 10 and anti 11) was formed
in 60% combined yield from the reaction of 1,2-hexadec-
anediol ditosylate and mesityl phosphide. The syn-to-
anti ratio was 0.9:1 on the basis of the integration of the
)
3.5 Hz, J P-C ) 17.5 Hz); the syn methyl group has small
3
1
P NMR spectrum of the product mixture. Assignment
When mesityl phosphide was reacted with (()-2,3-
butanediol ditosylate, a 52% yield of a racemic mixture
of trans-(()-1-mesityl-2,3-dimethylphosphiranes 3 and 4
of the stereochemistry of these two isomers was based
on the proton-coupled 31P NMR spectra. The chemical
shift of the syn isomer 10, -209.95 ppm, can be recog-
nized from the triplet due to coupling to the two anti ring-
(
Sch em e 6), with no detectable cis isomer, was isolated.
hydrogens with J P-H ) 17.7 Hz. The 31P signal for the
The stereochemistry was assigned by NMR. The syn ring
methyl is coupled weakly to phosphorus in the H (J P-H
1
anti isomer 11 at -220.45 ppm appears as a broad
singlet.
)
5.0 Hz) and 13C (J P-C ) 0 Hz) spectra, and the anti
ring methyl is coupled strongly to phosphorus (J P-H
)
An alkylphosphirane, 1-admantylphosphirane (12),
was synthesized in 27% isolated yield by the same
procedure.
1
3.8 Hz and J P-C ) 17.7 Hz). Since no cis isomer was
3
1
detected by P NMR in the reaction mixture before
purification, the stereoselectivity of the displacements
forming the P-C bonds appears to be >98%.
With meso-2,3-butanediol ditosylate as the starting
material, the product of reaction with the mesityl phos-
phide was revealed by 31P NMR spectroscopy to be a ca.
1:1 mixture of two cis epimers 5 and 6 (Scheme 7). Before
N
Evid en ce for Rin g F or m a tion by Tw o S 2 P r o-
cesses a n d th e Ster eoselective Syn th esis of P h os-
p h ir a n es. Reaction of a mixture of (()- and meso-2,3-
butanediol ditosylates with mesitylphosphine yielded all
three diastereomers (four optical isomers 3-6: two meso
compounds 5 and 6 and a pair of enantiomers 3 and 4)
Sch em e 5
Sch em e 6

Stereoselective Synthesis of Phosphiranes
J . Org. Chem., Vol. 61, No. 22, 1996 7705
Sch em e 7
Sch em e 9
as the starting material, yielding (2R,3R)-(-)-2,3-di-
methyl-1-mesitylphosphirane (4) of high optical purity
in 67% yield.16 Again the relative stereochemistry was
assigned by NMR and specific rotation [R] ) -27.32°,
D
and the absolute structure was determined later by X-ray
crystal structure analysis of a tungsten complex (24).
These structures confirmed that both carbon centers are
Sch em e 8
inverted during the reaction sequence of two S
processes.
N
2 reaction
Reaction of (2S)-(-)-1,2-propanediol ditosylate with
mesityl phosphide led to the formation of a pair of
3
1
diastereomers anti-(2R)- (15) ( P NMR δ -216.86 ppm)
3
1
and syn-(2R)-1-mesityl-2-methylphosphirane (16) ( P
NMR δ -208.38 ppm) in 98% combined yield. In this
case both 1-P and 2-C are chiral centers. The anti to syn
3
1
ratio is 1.3:1 on the basis of the integration of P NMR
signals. The phosphorus of the syn isomer 16 is coupled
3
1
to two anti ring protons, giving rise to a triplet P NMR
signal with J P-H ) 16.0 Hz, and the phosphorus of the
anti isomer 19a is coupled to the single anti ring proton
and to the three methyl protons, giving rise to a quintet
3
1
P NMR signal with J P-H ) 14.8 Hz. These isomers
could be separated only on a capillary GC column and
gave rise to identical mass spectra. While NMR and
high-resolution mass spectrometry were performed on
mixtures, the peaks in the NMR spectra could be as-
signed readily on the basis of their coupling constants
and intensities.
Syn th esis of P h osp h ir a n e-Tu n gsten P en ta ca r -
bon yl Com p lexes. After having synthesized several
new phosphiranes, preparation of their metal complexes
was undertaken. The complexing ability of phosphiranes
should be very high, because their cone angles are very
small. Marinetti, Ricard, and Mathey have prepared
several W and Mo complexes of phosphiranes via the
purification, 2.5% of a racemic mixture of trans isomers
3
and 4 was detected, giving a stereoselectivity of 97%.
The structure of 5 was first assigned by NMR and later
confirmed by X-ray crystal structure analysis of a tung-
sten complex (22). The two equivalent ring methyls of 5
are anti to the mesityl group, based on the methyl P-H
and P-C coupling constants (J P-H ) 13.2 Hz and J P-C
)
1
31
1
8.3 Hz). The H-coupled P NMR signal for 5 was split
into a clear 1:6:15:20:15:6:1 heptet by coupling with the
six ring methyl protons.
“
phospha-Wittig” reaction and also Rh complexes by
Having obtained trans-2,3-dimethyl-1-arylphosphiranes
from racemic (()-2,3-butanediol ditosylate and cis-2,3-
dimethyl-1-arylphosphiranes from meso-2,3-butanediol
ditosylate with a stereoselectivity of at least 97%, it was
clear that phosphirane formation is highly stereoselec-
4,5
complexation of the phosphiranes.
complexes should be useful as chiral catalysts and as
precursors of terminal phosphinidene complexes. X-ray
New phosphirane
5
17
crystal structure analysis of metal complexes facilitated
the study of the structure of difficult to crystalize
phosphiranes and the determination of the absolute
stereochemistry of chiral phosphiranes.
The starting material in these complexation reactions
6 6
was W(CO) . Irradiation of W(CO) in THF with a
N
tive, proceding either via two S 2 inversion steps, as was
established from the absolute configurations of the opti-
cally active phosphiranes discussed below, or by two
retention steps.
Syn th esis of Op tica lly Active P h osp h ir a n es. The
demonstration that phosphirane formation from phos-
phines and 2,3-butanediol ditosylates was highly stereo-
selective suggested that optically active phosphiranes
could be synthesized by this procedure (Scheme 8). When
optically pure (2R,3R)-(+)-2,3-butanediol ditosylate was
used, (2S,3S)-(+)-2,3-dimethyl-1-mesitylphosphirane (3)
of high optical purity was obtained in 53% yield.16 The
relative stereochemistry was assigned by NMR and
medium-pressure mercury lamp afforded a tungsten
pentacarbonyl-THF complex. The weakly bound THF
ligand can be replaced by many phosphiranes (Scheme
18
9
).
The five tungsten pentacarbonyl-phosphirane com-
plexes shown in Scheme 10, 17-21, have been synthe-
sized in yields of 47-74%. All the new complexes were
characterized by NMR and elemental analyses. The
phosphirane-tungsten complexes are much more stable
than the free phosphiranes and can be handled in air.
Tungsten pentacarbonyl complexes of phosphiranes with-
out substituents on the ring carbons were obtained as
specific rotation [R] ) +24.55°; the absolute configura-
D
tion was confirmed by X-ray crystal structure analysis
of a tungsten complex (23) described below.
The same experiment was carried out with com-
mercially available (2S,3S)-(-)-2,3-butanediol ditosylate
(17) Mercier, F.; Deschamps, b.; Mathey, F. J . Am. Chem. Soc. 1989,
1
11, 9098.
(16) While the optical purity was not directly measured, the high
(18) King, R. B.; Sadanani, A. D. Inorg. Chem. 1985, 24, 3136.
degree of stereospecificity (>97%) indicated by the absence of cis
isomers 5 and 6 implies an optical purity >97%.
Arndt, L. W.; Darensboutg, M. Y.; Delord, T.; Bancroft, B. T. J . Am.
Chem. Soc. 1986, 108, 2617.

7
706 J . Org. Chem., Vol. 61, No. 22, 1996
Li et al.
Sch em e 10
Sch em e 11
Sch em e 12
J
P-P ) 24.4 Hz. If the two phosphine ligands were trans
to each other, the J P-P should be in the range of 40-70
Hz.20
W(CO)
4
(PPh
3
2
)[(2S,3S)-(+)-MesP(CHMe) ] (23) was syn-
crystals. The tungsten pentacarbonyl complexes of phos-
phiranes with methyls on the ring carbons were either
oils or powders from which single crystals could not be
obtained.
thesized in 85% yield as pale yellow crystals. J P-P is 27.4
Hz, suggesting that triphenylphosphine is once again cis
to the phosphirane ligand. By using the same procedure
W(CO)
4
(PPh
3
2
)[(2R,3R)-(-)-MesP(CHMe) ] (24) was syn-
(
2S,3S)-(+)-MesP(CHMe)
2 5
W(CO) (20) and (2R,3R)-
thesized in 72% yield as pale yellow crystals. The NMR
spectra of this compound are identical to those of
compound 23.
Cr ysta l Str u ctu r e An a lysis of th e Tu n gsten P h os-
p h ir a n e Tr ip h en ylp h osp h in e Tetr a ca r bon yl Com -
p lexes. The three stereoisomeric complexes 22, 23, and
4 were structurally characterized by X-ray crystal-
lography.
4 3
For the complex W(CO) (PPh )[(2S,3R)-meso-MesP-
(
-)-MesP(CHMe) W(CO) (21) have identical NMR spec-
tra. Nonequivalent o-methyl protons are observed in the
H spectra, which suggests that the mesityl group cannot
2
5
1
rotate freely about the bond between the ipso carbon and
the phosphorus. In consequence, two different m-protons
were observed at 6.54 and 6.58 ppm, respectively, and
nonequivalent o-Ar carbons (141.4, 141.5 ppm) and m-Ar
2
1
3
carbons (129.0, 129.8 ppm) were observed in the C NMR
spectrum. An interesting observation was that all the
cis carbonyls are not equivalent by 13C NMR and appear
at 195.6, 196.4, and 197.3 ppm respectively.
(CHMe) (22), the ORTEP drawing (Figure 1, supporting
2
information) clearly reveals the S and R ring carbon
centers. The ORTEP drawing (Figure 2, supporting
information) of W(CO)
23) shows both S carbon centers in the phosphirane ring
clearly. The two ortho methyls in the mesityl group are
inequivalent, and the phenyl ring of mesityl is distorted.
These features are consistant with the observed solution
NMR spectra. The ORTEP drawing (Figure 3, support-
Syn th esis of Tu n gsten P h osp h ir a n e Tr ip h en yl-
p h osp h in e Tetr a ca r bon yl Com p lexes. One goal for
the synthesis of tungsten-phosphirane complexes was
to determine the absolute stereochemistry of the chiral
4
(PPh
3
2
)[(2S,3S)-(+)-MesP(CHMe) ]
(
(or pure meso) phosphiranes by X-ray diffraction analysis.
Having been unable to obtain crystals of the chiral
phosphirane-tungsten pentacarbonyl complexes, we de-
cided to replace one CO ligand with triphenylphosphine.
It was hoped that the bulky triphenylphosphine ligand
would help to produce crystals of X-ray quality. The
procedure was similar to that used for the pentacarbonyl
ing information) of W(CO)
4 3
(PPh )[(2R,3R)-(-)-MesP-
(
CHMe) ] (24) shows the two R ring carbon centers in
2
the phosphirane. The two ortho methyls on the mesityl
group are not equivalent, and the phenyl ring of the
mesityl is distorted.
complexes. W(CO)
5 3 6
PPh was prepared from W(CO) in
NMR Ch em ica l Sh ifts of P h osp h ir a n es. The 31P
NMR chemical shifts of phosphiranes are at very high
field, typically in the range of -50 to -350 ppm. This
1
9
high yield (Scheme 11) and was used as the starting
material in the following syntheses.
4 3 2
W(CO) (PPh )[(2S,3R)-meso-MesP(CHMe) ] (22) was
1
5
parallels the high-field chemical shifts observed in
N
synthesized in 77% yield (Scheme 12), and yellow crystals
were obtained. That triphenylphosphine is cis to the
phosphirane ligand is clear from the phosphorus-
phosphorus coupling constant in the 31P NMR spectrum,
2
9
NMR spectra of aziridines and Si NMR spectra of
siliranes. The effects of substituents on the 31P chemical
shifts of phosphiranes have been explained in both
(
20) Darensboutg, M. Y.; Delord, T.; Bancroft, B. T. J . Am. Chem.
(
19) Darensbourg, M. Y.; Conder, H. L.; Darensbourg, D. J .; Hasday,
Soc. 1986, 108, 2617. Schenk, W. A.; Buchner, W. Inorg. Chim. 1983,
70, 189.
C. J . Am. Chem. Soc. 1973, 95, 5919.

Stereoselective Synthesis of Phosphiranes
J . Org. Chem., Vol. 61, No. 22, 1996 7707
Ta ble 1. 31P Ch em ica l Sh ifts of P h osp h ir a n es
Atmosphere glovebox equipped with an He-493 dry-train
purifier or by using standard Schlenk or vacuum line tech-
niques. H (300 MHz), C (75.4 MHz), and P (121.4 MHz
unless specified as 202.3 MHz) NMR spectra employed C D
6 6
phosphirane
δ (ppm)
1
13
31
phenylphosphirane (7)
trans-(()-2,3-dimethyl-1-phenyl-
phosphirane (13, 14)
-237.00
-180.3
solvent unless otherwise stated. Elemental analyses were
performed by Galbraith Analytical Laboratories. Preparative
gas chromatography was performed on a chromatograph
constructed in this laboratory equipped with dual rhenium-
tunsten filaments (Gow-Mac code 13-002). Reaction products
were separated on a 5 ft × 0.25 in. aluminum column packed
with 5% SE-30 on Chromosorb W 60/80. Typical injection
temperatures were between 200 and 280 °C, and typical
column temperatures were in the range 100-200 °C. Flash
column chromatography was based on a published procedure,
with nitrogen as the pressurizing agent.23 Bottles with screw
caps were used to collect the fractions, and the collecting area
was blanketed by nitrogen. Yields given are based on the
weights of pure products isolated.
Ma ter ia ls. Unless otherwise indicated, all chemicals were
of reagent grade quality and used as supplied. Ethyl ether
and tetrahydrofuran were distilled from a blue solution of the
benzophenone sodium ketyl under nitrogen and used im-
mediately. Pentane, hexane, methylene chloride, and meth-
ylcyclohexane were distilled from calcium hydride. Pyridine
was distilled from sodium.
1
1
-mesitylphosphirane (1)
-mesityl-2-methylphosphirane
-240.8
-216.86 15 (anti)
-208.38 16 (syn)
-219.80 9 (anti)
-209.85 8 (syn)
-220.45 11 (anti)
-209.86 10 (syn)
-199.43 5 (anti,cis)
-196.30 6 (syn,cis)
1
5 (anti), 16 (syn)
-mesityl-2-propylphosphirane
(syn), 9 (anti)
-mesityl-2-n-tetradecylphosphirane
0 (syn), 11 (anti)
,3-dimethyl-1-mesitylphosphirane
, 4 (trans), 5 (anti,cis), 6 (syn,cis)
1
1
2
8
1
3
-186.18 3, 4 (trans)
electronic and steric terms.21 We found that methyl
substituents on the carbons of the phosphirane ring lead
to a lower field 31P chemical shift. Selected data are
shown in Table 1. It should be noted that the chemical
shift for the anti diastereomer is in each case at higher
field than the signal for the syn stereoisomer. This
observation could be useful in the assignment of stere-
ochemistry.
Mesitylp h osp h in e. This compound was synthesized by
The 13C resonances of the ring carbons of phosphiranes
the method of Oshikawa and Yamashita.24
are also at high field: δ is 0.7 ppm for the parent
(
2,4,6-Tr i-ter t-bu tylp h en yl)p h osp h in e. This compound
4
phosphirane (C
2
H
4
PH) and 1.2 ppm for adamantylphos-
25
was prepared by the method of Cowley et al.
phirane 12. This phenomenon has been observed for
other three-membered rings as well.
A large value of the phosphorus-carbon coupling
constant (J P-C) is characteristic of phosphiranes. For
compounds studied in this laboratory, their range is 30-
Ad m a n tylp h osp h in e. This compound was synthesized by
2
6 31
the procedure of Stetter and Last:
) 188.9 Hz); H NMR δ 1.4-1.8 (m, 15 H), 2.68 (d, 2 H, J P-H
188.3 Hz).
P NMR δ -82.42 (J P-H
1
)
The following 2,3-butanediol ditosylates were synthesized
from the corresponding diols by the procedure of Corey and
Mitra:27 ((, m eso)-2,3-bu ta n ed iol d itosyla te; (()-2,3-bu -
t a n ed iol d it osyla t e; m eso-2,3-b u t a n ed iol d it osyla t e;
5
0 Hz. Coupling constants as large as 82.1 Hz have been
1
8
reported by others.
Ma ss Sp ectr a of P h osp h ir a n es. Mass spectra were
28
(
2S,3S)-(-)-2,3-bu ta n ed iol d itosyla te; (2R,3R)-(+)-2,3-
+
28
recorded for all phosphiranes synthesized, and M was
bu ta n ed iol d itosyla te.
generally an ion of significant intensity. Fragment ions
corresponding in mass to phosphinidene cations are
frequently the base peaks. Selected MS data are given
in Table 2.
This fragmantation suggests that phosphiranes are
prone to thermal decomposition that extrudes phosphin-
idenes. This aspect of the work will be reported as a
series of pyrolysis experiments and kinetic studies.22
(S)-(-)-P r op a n ed iol Ditosyla te. This compound was
made in 87% yield from (S)-(+)-propanediol by the procedure
of Fryzuk and Bosnich:29 1H NMR δ 0.88 (d, 3 H, J H-H ) 6.5
Hz), 1.92 (s, 6 H), 3.73 (m, 2 H), 4.53 (dt, 1 H, J H-H ) 6.5 Hz),
6
.80 (d, 4 H, J H-H ) 7.8 Hz), 7.64 (d, 2 H, J H-H ) 8.3 Hz), 7.69
13 1
(
1
d, 2 H, J H-H ) 8.3 Hz); C{ H} NMR δ 16.9, 21.2, 70.7, 75.6,
28.1, 129.9, 130.0, 133.2, 134.4, 144.7, 144.9.
,2-P en ta n ed iol d itosyla te was synthesized in 80% yield
1
by the method of Fryzuk and Bosnich from 1,2-pentane-
diol:30 1H NMR δ 0.56 (t, 3 H, J H-H ) 7.3 Hz), 0.85-1.48 (m,
4
)
8
1
1
H), 1.92 (s, 6 H, 3.85-4.00 (m, 2 H), 4.57 (sextet, 1 H, J H-H
Con clu sion
4.9 Hz), 6.81 (d, 4 H, J H-H ) 7.8 Hz), 7.68 (d, 2 H, J H-H )
.3 Hz), 7.74 (d, 2 H, J H-H ) 8.3 Hz); 13C{ H} NMR δ 13.5,
8.1, 21.2, 33.2, 69.9, 78.9, 128.1, 128.2, 129.9, 130.0, 133.3,
34.5, 144.7, 144.9.
1
In summary, an efficient and general method for the
synthesis of phosphiranes was developed and employed
to synthesize a series of new compounds. The stereose-
lectivity of this method was established, and it allows
chiral phosphiranes to be conveniently synthesized for
the first time. Phosphirane diastereomers can be easily
distinguished on the basis of their J P-H and J P-C NMR
coupling constants. Phosphiranes can be easily trans-
formed into their tungsten carbonyl complexes. The
X-ray crystal structure analysis of the phosphirane-
triphenylphosphine-tungsten tetracarbonyl complexes
established the absolute stereochemistry of the pure
chiral and meso phosphiranes unambiguously. The
displacement steps in the phosphirane synthesis are all
inversions.
1
,2-Hexa d eca n ed iol d itosyla te was synthesized in 85%
2
9 1
yield by the same method from 1,2-hexadecanediol: H NMR
δ 0.90-1.42 (m, 29 H), 1.88 (s, 6 H), 3.93 (m, 2 H), 4.57 (bs, 1
H), 6.76 (d, 4 H, J H-H ) 5.6 Hz), 7.67 (d, 2 H, J H-H ) 7.7 Hz),
7.73 (d, 2 H, J H-H ) 7.6 Hz).
1-P h en ylp h osp h ir a n e (7). A solution of phenylphosphine
(3.0 g, 27.2 mmol) in 100 mL of THF was placed in a 250 mL-
flask equipped with a magnetic stirring bar and a rubber
septum and cooled to 0 °C with ice water. A hexane solution
of n-BuLi (18 mL, 1.6 M, 28.8 mmol) was added by syringe
over 15 min. The mixture was allowed to warm to room
temperature and was stirred for 30 min, producing a solution
of fresh monolithium phosphide. The solution of PhPHLi was
added dropwise over a 1 h period to a stirred solution of
Exp er im en ta l Section
(23) Still, W. C.; Kahn, M.; Mitra, A. J . Org. Chem. 1978, 43, 2923.
(24) Oshikawa, T.; Yamashita, M. Chem. Ind. 1985, 126.
Gen er a l Meth od s. Unless otherwise noted, all manipula-
tions were carried out under an inert atmosphere in a Vacuum
(25) Cowley, A. H.; Norman, N. C.; Pakulski, M. Inorg. Synth. 1990,
7, 235.
2
(26) Stetter, H.; Last, W.-D. Chem. Ber. 1969, 102, 3364.
(
27) Corey, E. J .; Mitra, R. B. J . Am. Chem. Soc. 1962, 84, 2938.
(
(
21) Niecke, E.; Leuer, M.; Nieger, M. Chem. Ber. 1989, 122, 453.
22) Li, X.; Gaspar, P. P. Pyrolysis of Phosphiranes and the Mech-
(28) Kottner, J .; Greber, G. Chem. Ber. 1980, 113, 2323.
(29) Fryzuk, M. D.; Bosnich, B. J . Am. Chem. Soc. 1977, 99, 6262.
(30) Fryzuk, M. D.; Bosnich, B. J . Am. Chem. Soc. 1978, 100, 5491.
anism of Phosphinidene Addition to Olefins, to be published.

7
708 J . Org. Chem., Vol. 61, No. 22, 1996
Li et al.
Ta ble 2. Selected MS Da ta for P h osp h ir a n es
M+ mass and
+
“R-P ” mass and
phosphirane and ionization mode
relative intensity
relative intensity
phenylphosphirane (7) (EI)
trans-(()-2,3-dimethyl-1-phenylphosphirane (13, 14) (EI)
136 (66)
164 (57)
178 (38)
192 (48)
220 (21)
206 (37)
194 (7)
108 (100)
108 (100)
150 (100)
150 (100)
150 (100)
150 (100)
166 (0.8)
276 (16)
1
1
1
2
1
1
-mesitylphosphirane (1) (EI)
-mesityl-2-methylphosphirane 15 (anti), 16 (syn) (EI)
-mesityl-2-propylphosphirane 8 (syn), 9 (anti) (EI)
,3-dimethyl-1-mesitylphosphirane 3, 4 (trans), 5 (anti,cis), 6 (syn,cis) (EI)
-adamantylphosphirane (12) (EI)
-supermesitylphosphirane (2) (CI)
304 (1.2)
ethylene glycol ditosylate (11.9 g, 32 mmol) in 150 mL of THF
at 0 °C in a 500 mL flask. When addition was complete, the
mixture was allowed to warm room temperature. After a
further 2 h the reaction mixture was again cooled to 0 °C, and
a hexane solution of n-BuLi (20 mL, 1.6 M, 32 mmol) was
added by syringe over 15 min. After addition was complete,
the reaction mixture was warmed to room temperature. After
mixture by 31P NMR indicated the formation of MesPHCH
CH(OTs)(CH and CH (OTs)CH(MesPH)(CH
31P
2
-
2
)13CH
3
2
2 3
)13CH :
NMR (THF) δ -98.7 to -101.6 (four peaks). The reaction
mixture was again cooled to -5 to 0 °C, and another equivalent
of n-BuLi (8 mL, 1.6 M, 12.8 mmol) was added dropwise over
15 min. After addition was complete, the reaction mixture was
allowed to warm to room temperature. After a further 10 h,
a pair of phosphirane diastereomers 10 and 11 were the only
products observable by 31P NMR, which indicated that the
reaction was complete. Solvent was removed in vacuo, and
the remaining material was mixed with 400 mL of cyclohex-
ane/pentane (1:2) and filtered to remove lithium tosylate.
After evaporation of the hexane from the filtrate, the residue
was chromatographed on silica gel with pentane/ether (9:1)
3
1
a further 3 h, P NMR indicated that the reaction was
complete. THF was removed in vacuo, and the residue was
mixed with 100 mL of pentane and filtered to remove lithium
tosylate. After evaporation of pentane from the filtrate, the
residue was distilled in vacuo (50-60 °C/1 Torr), yielding
3
1
1
-phenylphosphirane (7) (2.5 g, 68%) as a colorless liquid:
P
7
13
1
NMR (202.3 MHz) δ -237.0 (lit. δ -234, -236 ); H NMR δ
0
7
{
.87-0.95 (m, 2 H), 1.00-1.06 (m, 2 H), 6.8-7.0 (m, 3 H),
f
eluent (R ) 0.51), yielding 1-mesityl-2-n-tetradecylphos-
7
13
.15-7.25 (m, 2 H) (lit. δ 0.3-1.0 (4 H)), 6.5-7.2 (5 H); C-
phirane (10 + 11) (2.2 g, 60%) as a white wax. Both 10 and
11 decomposed in the GC at ca. 200-210 °C, forming hexa-
decene as the major product, but a mass spectrum of the
mixture of stereoisomers was obtained via a solid sample
1
H} δ 10.0 (d, J P-C ) 39.8 Hz), 128.4, 128.5, 128.7 (bs), 131.9
+
(
d, J P-C ) 19.4 Hz); exact mass determination for C
7
H
9
P (M ),
calcd 136.0442, found 136.0448.
1
-Mesityl-2-p r op ylp h osp h ir a n e (syn 8, a n ti 9). The
probe: 31P NMR (CDCl
-220.45 (anti 11); H NMR δ 0.89 (t, 3 H, J H-H ) 6.6 Hz),
1.26 (s, 26 H), 2.22 (s, 3 H), 2.49 (s, 6 H), 6.78 (s, 1 H); exact
mass determination for C25
374.3071.
3
) δ -209.86 (syn 10, J P-H ) 17.7 Hz),
1
same procedure was followed with a solution of mesitylphos-
phine (2.0 g, 13.2 mmol) in 150 mL of THF, a hexane solution
of n-butyllithium (5.5 mL, 2.5 M, 13.8 mmol), and a solution
of 1,2-pentanediol ditosylate (5.8 g, 14.0 mmol) in 100 mL of
THF. After 2 h, the reaction mixture was again cooled to -5
to 0 °C, and another equivalent of n-BuLi (6 mL, 2.5 M, 15.0
mmol) was added. After a further 10 h at room temperature,
a pair of phosphirane diastereomers, 8 and 9 (1:1 ratio), were
+
H
43P (M ), calcd 374.3102, found
1-Ad m a n tylp h osp h ir a n e (12). The same procedure was
employed with admantylphosphine (1.0 g, 5.95 mmol) and
ethylene glycol ditosylate (2.3 g, 6.2 mmol). When reaction
was complete, THF was removed in vacuo, and the residue
was mixed with 100 mL of pentane and filtered to remove
lithium tosylate. After evaporation of pentane from the
filtrate, the residue was transfered into a drybox and was
chromatographed on silica gel with pentane as eluent, yielding
1-adamantylphosphirane (0.30 g, 27%) as a colorless oil. 12
is unstable toward air and silica gel, and the low yield of
isolated product was due to decomposition and oxidation
3
1
the only products observable by P NMR, which indicated that
the reaction was complete. Solvent was removed in vacuo, and
the remaining material was mixed with 150 mL of pentane
and filtered to remove lithium tosylate. After evaporation of
the hexane from the filtrate, the residue was chromatographed
on silica gel with pentane eluent, yielding a mixture of
1
-mesityl-2-propylphosphiranes 8 and 9 (0.7 g, 24%) as a
3
1
colorless oil. The low yield was due to oxidation during
during isolation.
mixture indicated a high yield. After purification 12 was
P NMR analysis of the crude reaction
workup. The two diastereomers were separated by prepara-
1
31
1
tive gas chromatography on a 5 × /
4
in. o.d. aluminum column
stable for months in the freezer: P NMR δ -208.16; H NMR
with a packing consisting of 5% SE-30 on 60/80 mesh Chro-
mosorb W operated at 150 °C. The anti isomer 9 was obtained
in pure form, but the syn isomer 8 was collected as a 70:30
mixture with the anti isomer 9. syn-1-Mesityl-2-propylphos-
δ 0.52 (dm, 2 H, J P-H ) 16.5 Hz), 0.82 (m, 2 H), 1.14-1.73 (m,
15 H); 13C{ H} NMR δ 1.2 (d, J P-C ) 42.9 Hz), 29.0 (d, J P-C
1
)
7.8 Hz), 37.0, 40.7 (d, J P-C ) 12.7 Hz); exact mass determi-
+
nation for C12H19P (M ) calcd 194.1224, found 194.1222.
3
1
1
phirane (8): P δ -209.85 (t, J P-H ) 17.5 Hz); H NMR δ 0.57
m, 1 H), 0.72 (t, 3 H, J H-H ) 7.4 Hz), 0.82 (m, 1 H), 1.24-
.60 (m, 4 H), 1.79 (m, 1 H), 2.06 (s, 3 H), 2.45 (bs, 6H), 6.67
((,m eso)-2,3-Dim eth yl-1-m esitylp h osp h ir a n es (a m ix-
tu r e of 3, 4, 5, a n d 6). A similar procedure was employed
with a solution of mesitylphosphine (2.0 g, 13.2 mmol) in 120
mL of THF and a hexane solution of n-BuLi (8.3 mL, 1.6 M,
13.3 mmol). Formation of monolithium mesityl phosphide was
indicated by 31P NMR (THF) δ -155.3 ppm (d, J P-H ) 168
Hz). The solution of monolithium mesityl phosphide was
added dropwise over 30 min to a stirred solution of 2,3-
butanediol ditosylate (5.6 g, 14.0 mmol) in 200 mL of THF
cooled to 0 °C in a 500 mL flask. After 3 h at room
temperature, the reaction mixture was again cooled to 0 °C,
and another equivalent of n-BuLi (9 mL, 1.6 M, 14.4 mmol)
was added dropwise over 15 min. After 5-10 h at room
temperature, monitoring the appearance of the phosphirane
product by 31P NMR indicated that the reaction was complete
(product ratio 3,4:5:6 ca. 1:1:1). Solvent was removed in vacuo,
and the remaining material was mixed with 200 mL of pentane
and filtered to remove lithium tosylate. After evaporation of
the pentane from the filtrate, the residue was chromatograped
as described above. 6 largely decomposed during workup. A
mixture of stereoisomeric 2,3-dimethyl-1-mesitylphosphiranes
3-6 was obtained in 60% yield. These isomers could not be
separated, and the mixture was subjected to NMR spectros-
(
1
1
3
1
(
s, 2 H); C{ H} NMR δ 14.0, 15.5 (d, J P-C ) 37.4 Hz), 21.0,
2
1
2.7 (bd, J P-C ) 15.0 Hz), 24.4, 24.6 (d, J P-C ) 44.3 Hz), 33.3,
29.4 (bs), 132.4 (d, J P-C ) 44.3 Hz), 137.1, 143.0 (bs); exact
+
mass determination for C14
H
21P (M ), calcd 220.1381, found
3
1
2
20.1383. a n ti-1-Mesityl-2-p r op ylp h osp h ir a n e (9):
P
NMR δ -219.80 (poorly resolved multiplet due to coupling with
several protons of propyl group as well as with single anti ring
1
proton); H NMR δ 0.87 (t, 3 H, J H-H ) 7.0 Hz), 1.05 (m, 1 H),
1
6
2
J
.20 (m, 1 H), 1.30-1.60 (m, 5 H), 2.08 (s, 3 H), 2.46 (s, 6 H),
13 1
.67 (s, 2 H); C{ H} NMR δ 14.3, 20.9 (d, J P-C ) 39.0 Hz),
1.0, 22.5 (d, J P-C ) 8.9 Hz), 23.4 (d, J P-C ) 6.1 Hz), 29.1 (d,
P-C ) 37.9 Hz), 36.8 (d, J P-C ) 16.3), 128.8, 136.2 (d, J P-C
)
4
0.6 Hz), 137.1, 142.2 (d, J P-C ) 9.6 Hz); exact mass deter-
+
mination for C14
-Mesityl-2-n -tetr adecylph osph ir an e (10, 11). The same
procedure was followed with a solution of mesitylphosphine
1.5 g, 9.9 mmol) in 120 mL of THF, a hexane solution of
H21P (M ), calcd 220.1381, found 220.1383.
1
(
n-butyllithium (6.3 mL, 1.6 M, 10.1 mmol), and a solution of
hexadecanediol ditosylate (6.3 g, 11.1 mmol) in 100 mL of THF.
After 1.5 h at room temperature, monitoring of the reaction

Stereoselective Synthesis of Phosphiranes
J . Org. Chem., Vol. 61, No. 22, 1996 7709
copy: 31P NMR δ -196.30 (t, J H-P ) 19 Hz, syn-cis, 6 minor),
C
H
19P (M ), calcd 206.1224, found 206.1222; [a]
) 3.86, methylcyclohexane.
+
) 24.55, c
13
D
-
199.43 (heptet, J P-H ) 13.0 Hz), anti-cis 5), -186.18 (bs,
1
trans-(() 3, 4); H NMR δ 0.90-1.50 (m, 1 H), 1.62 (m, 1 H),
(2R,3R)-(-)-Mesityl-2,3-d im eth ylp h osp h ir a n e (4). The
same procedure was followed with mesitylphosphine (2.0 g,
13.2 mmol) and (2S,3S)-(-)-2,3-butanediol ditosylate (6.3 g,
15.8 mmol). Distillation under high vacum yielded (2R,3R)-
(-)-1-mesityl-2,3-dimethylphosphirane (4) (1.8 g, 67%) as a
0
.99-1.30 (m, 6 H), 2.08 (s, 3 H), 2.44 (s, 6 H), 6.68 (s, 2 H);
1
3
1
C{ H} NMR δ 12.4 (d, J P-C ) 18.9 Hz), 15.2, 18.3 (d, J P-C
)
1
1
7.6 Hz), 20.6, 21.8 (d, J P-C ) 8.9 Hz), 28.5 - 29.4, 128.8, 129.4,
36.9, 142.2 (d, J P-C ) 9.4 Hz), 143.2 (d, J P-C ) 9.4 Hz).
colorless oil: NMR data are identical with those for the racemic
tr a n s-(()-2,3-Dim eth yl-1-p h en ylp h osp h ir a n e (13, 14).
+
mixture; exact mass determination for C13
06.1224, found 206.1223; [a]
clohexane.
(2R)-1-Mesityl-2-m eth ylp h osp h ir a n es 15, 16. The same
procedure was followed with mesitylphosphine (0.8 g, 5.3
mmol) and (2S)-(-)-1,2-propanediol ditosylate (3.0 g, 8.0
mmol). A mixture of (2R)-1-mesityl-2-methylphosphirane
diastereomers 15, 16 (1.0 g, 98%) was obtained by chroma-
tography as a colorless oil that could not be separated. Spectra
of the mixture were recorded. a n ti-(2R)-1-Mesityl-2-m eth -
H
19P (M ), calcd
The same procedure was employed with a THF solution of
phenylphosphine (3.0 g, 27.2 mmol), a hexane solution of
n-BuLi (18 mL, 1.6 M, 28.8 mmol), and a solution of 2,3-
butanediol ditosylate (racemic mixture, 13.0 g, 32.0 mmol) in
2
D
) -27.32, c ) 3.45, methylcy-
1
50 mL of THF. After 3 h at room temperature, the reaction
mixture was treated at 0 °C with a hexane solution of n-BuLi
(
20 mL, 1.6 M, 32 mmol). After 10 h at room temperature,
P NMR indicated that the reaction was complete. THF was
3
1
removed in vacuo, and the residue was mixed with 150 mL of
pentane and filtered to remove lithium tosylate. After evapo-
ration of pentane from the filtrate, the product was obtained
upon vacuum distillation in 90% yield as a colorless liquid.
Product of high purity was obtained by chromatography as
described above (2.0 g, 45%). The product is readily oxidized,
but if the compound is very pure or in solution, it can be stored
3
1
ylp h osp h ir a n e (15): P NMR δ 216.86 (p, J P-H ) 14.8 Hz);
1
H NMR δ 0.7-1.5 (m, 3 H), 1.21 (dd, 3 H, J P-H ) 13.9 Hz,
1
3
J
{
H-H ) 6.5 Hz), 2.08 (s, 3 H), 2.43 (s, 6 H), 6.65 (s, 2 H); C-
1
H} NMR δ 18.9 (d, J P-C ) 18.3 Hz), 19.1 (d, J P-C ) 44.0
Hz), 21.0, 22.4 (d, J P-C ) 9.0 Hz), 23.2 (d, J P-C ) 37.0 Hz),
3
1
128.8, 136.1 (d, J P-C ) 39.8 Hz), 137.0, 142.1 (d, J
P-C
) 9.4
in a freezer under N
2
for months. 13, 14: P NMR δ -180.3;
+
1
Hz); exact mass determination for C H P (M ), calcd 192.1068,
H NMR δ 0.91 (dd, 3 H, J P-H ) 7.4 Hz, J H-H ) 7.4 Hz), 0.95-
12 17
found 192.1071. syn -(2R)-1-Mesityl-2-m eth ylp h osp h ir a n e
1
.10 (m, 1 H), 1.18 (dd, 3 H, J P-H ) 13.5 Hz, J H-H ) 6.4 Hz),
.41-1.50 (m, 1 H), 6.95-7.00 (m, 3 H), 7.24-7.30 (m, 2 H);
(
16): 31P NMR δ 208.38 (t, J P-H ) 16.0 Hz); H NMR δ 0.70-
1
1
1
3
1
1.50 (m, 3 H), 0.97 (dd, 3 H, J P-H ) 5.0 Hz, J H-H ) 6.2 Hz),
C{ H} NMR δ 15.7, 18.9 (d, J P-C ) 17.5 Hz), 26.2 (d, J P-C
)
1
3
1
2
1
J
.08 (s, 3 H), 2.43 (bs, 6 H), 6.65 (s, 2 H); C{ H} NMR δ 16.0,
8.8 (d, J P-C ) 37.8 Hz), 21.0, 22.4 (d, J P-C ) 9.0 Hz), 22.4 (d,
3
1
5.4 Hz), 27.3 (d, J P-C ) 41.2 Hz), 128.2 (d, J P-C ) 7.7 Hz),
28.7 - 129.3, 134.3 (d, J P-C ) 14.9 Hz), 137.3 (d, J P-C ) 42.2
+
P-C ) 39.2 Hz), 129.3 (bs), 132.0 (d, J P-C ) 44.5 Hz), 137.0,
Hz); exact mass determination for C10
found 164.0756.
H
13P (M ), calcd 164.0755,
+
1
1
43.1 (bs); exact mass determination for C12
92.1068, found 192.1071.
H
17P (M ), calcd
(
()-2,3-Dim eth yl-1-m esitylp h osp h ir a n e (r a cem ic m ix-
P h P (CH
2 2 5 6
CH )W(CO) (17). A solution of W(CO) (0.78 g,
.22 mmol) in 200 mL of THF was placed in a Pyrex photolysis
tu r e of 3 a n d 4). The same procedure was followed with
mesitylphosphine (16) (2.0 g, 13.2 mmol) and (()-2,3-butane-
diol ditosylate (5.6 g, 14.0 mmol) as starting materials. When
reaction was complete, THF was removed in vacuo, and the
remaining material was mixed with 200 mL of pentane and
filtered to remove lithium tosylate. After evaporation of the
pentane from the filtrate, the residue was chromatographed
2
tube (o.d. ) 4.5 cm, length ) 22 cm) with a magnetic stirring
bar and degassed with three freeze-pump-thaw cycles. The
mixture was irradiated for 6 h with a medium-pressure
mercury lamp with stirring. Phenylphosphirane (7) (0.3 g, 2.2
mmol) in 20 mL of THF was placed in a 500 mL flask equipped
with a rubber septum and a magnetic stirring bar. The freshly
prepared yellow-orange THF solution of W(CO) (THF) was
5
transfered to this reaction flask with a double needle with
stirring at room temperature. After being stirred a further
0 h, the mixture turned from orange to nearly colorless, and
P NMR indicated the reaction was complete. Solvent was
removed under vacuo, and the remaining material was mixed
with 40 mL of pentane and filtered to remove the residue. After
evaporation of the pentane from the filtrate, the residue was
on silica gel with pentane eluent (R
f
) 0.35). Pure product
31 1
(
1.4 g, 52%) was obtained as a colorless oil: P δ -186.20; H
NMR δ: 1.01 (dd, 3 H, J P-H ) 5.0 Hz, J H-H ) 6.2 Hz), 1.10-
1
2
(
J
J
(
(
(
.35 (m, 2 H), 1.27 (dd, 3 H, J P-H ) 13.8 Hz, J H-H ) 6.3 Hz),
1
13 1
.08 (s, 3 H), 2.42 (bs, 6 H), 6.69 (s, 2 H); C{ H} δ 15.6, 18.7
3
1
d, J P-C ) 17.7 Hz), 21.0, 22.5 (bd, J P-C ) 37.6 Hz), 29.1 (d,
P-C ) 34.3 Hz), 29.5 (d, J P-C ) 43.0 Hz), 129.3 (bs), 132.1 (d,
P-C ) 43.7 Hz), 136.9, 143.2; UV (cyclohexane) λmax 284 nm
3
3
ꢀ ) 1.564 × 10 ), 275 nm (ꢀ ) 1.631 × 10 ), shoulder 246 nm
recrystallized from pentane/ether (9:1), yielding white crystal-
3
ꢀ ) 8.985 × 10 ); exact mass determination (EI) for C13
H
19
P
31
line product 17 (0.75 g, 74%): P NMR δ -187.78 (J P-W
)
+
M ), calcd 206.1244, found 206.1220. Anal. Calcd for
1
2
7
56.9 Hz); H NMR δ 0.82 (m, 2 H), 0.89-0.95 (m, 2 H), 6.84-
C
13
H
19P: C, 75.70; H, 9.28. Found: C, 74.77; H, 9.39.
m eso-a n ti-cis-1-Mesityl-2,3-d im eth ylp h osp h ir a n e (5).
The same procedure was followed with mesitylphosphine (16)
2.0 g, 13.2 mmol) and meso-2,3-butanediol ditosylate (5.6 g,
4.0 mmol). Chromatography on silica gel with pentane eluent
) 0.38), yielded meso-anti-1-mesityl-2,3-dimethylphos-
13 1
.02 (m, 5 H); C{ H} NMR δ 10.7 (d, J P-C ) 12.4 Hz), 128.8
(
1
d, J P-C ) 10.4 Hz), 130.3 (d, J P-C ) 2.4 Hz, 131.4 (d, J P-C
)
3.3 Hz), 196.0 (d, J P-C ) 8.4 Hz), 198.0 (d, J P-C ) 30.2 Hz).
(
1
(R
f
Anal. Calcd for C13
3.97; H, 2.06.
Mes*P (CH
followed with a solution of W(CO)
mL of THF and a solution of 1-supermesitylphosphirane (2)
0.43 g, 1.41 mmol) in 50 mL of THF. Product was extracted
9 5
H O PW: C, 33.92; H, 1.97. Found: C,
3
2
CH
2
)W(CO)
5
(18). The same procedure was
(0.5 g, 1.42 mmol) in 150
phirane (5) (0.8 g, 30%) as a colorless oil. meso-syn-cis-1-
Mesityl-2,3-dimethylphosphirane (6) was present in the crude
mixture in a nearly 1:1 ratio with the meso-anti-cis isomer 5,
but 6 decomposed completely during workup, and phosphin-
idene oligomers were observed as decomposition products. 5:
6
(
with 50 mL of pentane and 10 mL of ether and recrystallized
from pentane/ether (9:1) at -20 °C, giving dark brown crystals
3
1
1
31
1
P{ H} δ -199.56; P NMR δ (heptet, J P-H ) 13.0 Hz); H
31
of 18 (0.42 g, 47%): P NMR δ -201.62 (J P-W ) 258.7 Hz);
NMR δ 1.26 (dd, 6 H, J P-H ) 13.2 Hz, J H-H ) 5.5 Hz), 1.62
(
1
H NMR δ 1.00-1.20 (m, 4 H), 1.18 (s, 9 H), 1.58 (s, 18 H),
1
3
1
m, 2 H), 2.08 (s, 3 H), 2.45 (s, 6 H), 6.67 (s, 2 H); C{ H}
13
1
7
1
J
.28 (d, 2 H, J P-H ) 3.7 Hz); C{ H} NMR δ 22.4 (d, J P-C )
NMR δ 12.8 (d, J P-C ) 18.3 Hz), 20.1, 22.2 (d, J P-C ) 9.0 Hz),
1.1 Hz), 31.1, 34.8 (d, J P-C ) 2.9 Hz), 36.2, 39.9 (s), 123.5 (d,
P-C ) 7.2 Hz), 150.8 (d, J P-C ) 2.3 Hz), 157.8 (d, J P-C ) 4.2
2
1
9.3 (d, J P-C ) 36.3 Hz), 128.8, 136.3 (d, J P-C ) 38.6 Hz), 136.9,
42.2 (d, J P-C ) 9.2 Hz); exact mass determination for C13
19
H P
Hz), 198.0 (d, J P-C ) 7.1 Hz), 198.4. Anal. Calcd for C25
PW: C, 47.79; H, 5.29. Found: C, 47.49; H, 5.73.
33 5
H O -
+
(
M ), calcd 206.1224, found 206.1229.
2S,3S)-(+)-1-Mesityl-2,3-dim eth ylph osph ir an e (3). The
same procedure was followed with mesitylphosphine (1.4 g,
(
(2S,3R)-m eso-MesP (CHMe)
cedure was followed with a solution of W(CO)
mmol) in 100 mL of THF and a solution of meso-(2S,3R)-anti-
cis-MesP(CHMe) (5) (0.1 g, 0.49 mmol) in 10 mL of THF. The
2
W(CO)
5
(19). The same pro-
6
(0.20 g, 0.57
9
.2 mmol) and (2R,3R)-(+)-2,3-butanediol ditosylate (4.3 g, 10.8
mmol). Distillation under high vacum and column chroma-
2
tography yielded (2S,3S)-(+)-1-mesityl-2,3-dimethylphosphirane
product was extracted with 100 mL of pentane and chromato-
(
3) (1.0 g, 53%) as a colorless oil: NMR data are identical with
graphed on silica gel with pentane-ether (95:5) as eluent,
3
1
those for the racemic mixture; exact mass determination for
yielding 19 as a light pink powder (0.16 g, 59%): P NMR δ

7
710 J . Org. Chem., Vol. 61, No. 22, 1996
Li et al.
1
1
-
162.75 (J P-W ) 254.2 Hz); H NMR δ 1.05 (ddd, 6 H, J P-H
)
21.28 (dd, 1 P, J P-P ) 24.4 Hz, J P-W ) 238.0 Hz, Ph
NMR (CDCl
1.71 (m, 2 H), 2.23 (s, 3 H), 2.29 (s, 6 H), 6.77 (d, 2 H, J P-H
3
P); H
1
1
{
7.9 Hz, J H-H ) 6.4 Hz, J H′-H ) 2.1 Hz), 1.25-1.33 (m, 2 H),
3
) δ 1.29 (dd, 6 H, J P-H ) 16.5 Hz, J H-H ) 6.1 Hz),
.96 (s, 3 H), 2.35 (s, 6 H), 6.54 (d, 2 H, J P-H ) 3.4 Hz); 13C-
)
1
13
1
H} NMR δ 11.0 (d, J P-C ) 3.0 Hz), 20.9, 21.5 (d, J P-C ) 8.6
2.7 Hz), 7.26-7.39 (m, 15 H); C{ H} NMR (CDCl
3
) δ 11.4
Hz), 26.7 (d, J P-C ) 12.7 Hz), 129.3 (d, J P-C ) 7.0 Hz), 132.4
(s), 21.0, 22.1 (d, J P-C ) 7.0 Hz), 28.1 (d, J P-C ) 12.6 Hz), 128.0
(d, J P-C ) 9.5 Hz), 129.0 (m), 129.7, 133.5 (d, J P-C ) 12.0 Hz),
136.6 (d, J P-C ) 37.1 Hz), 138.9, 141.3 (d, J P-C ) 8.7 Hz), 201.7
(
J
d, J P-C ) 33.0 Hz), 139.8, 140.7 (d, J P-C ) 8.3 Hz), 196.0 (d,
P-C ) 8.0 Hz), 197.5 (d, J P-C ) 28.4 Hz). Anal. Calcd for
C
18
H
19
O
5
PW: C, 40.78; H, 3.61. Found: C, 40.82; H, 3.73.
34 4 2
(m), 203.7 (d, J P-C ) 16.9 Hz). Anal. Calcd for C35H O P W:
(
2S,3S)-(+)-MesP (CHMe)
dure and the same amounts of materials were used for the
2
W(CO) (20). The same proce-
5
C, 54.99; H, 4.48. Found: C, 55.01; H, 4.46.
W(CO)
4
(P P h
3
2
)[(2S,3S)-(+)-MesP (CHMe) ] (23). The same
preparation of 20 from 3. Pure 20 (0.18 g, 67%) was obtained
as a pale yellow oil: P NMR δ -156.18 (J P-W ) 252.5 Hz);
procedure and same amounts of starting materials were used
for the preparation of 23 from 3. Product was extracted with
150 mL of pentane/ether (8:2) and recrystallized from a
mixture of pentane and ether (1:1) at -5 to 10 °C. X-ray
3
1
1
H NMR δ 0.69-0.80 (m, 1 H), 0.81 (dd, 3 H, J P-H ) 13.4 Hz,
J
H-H ) 6.4 Hz), 1.00-1.11 (m, 1 H), 1.19 (dd, 3 H, J P-H ) 18.1
Hz, J H-H ) 6.7 Hz), 1.97 (s, 3 H), 2.31 (s, 3 H), 2.40 (s, 3 H),
quality light yellow crystals of 23 were obtained (0.22 g,
1
3
1
31
6
.54 (s, 1 H), 6.58 (s, 1 H); C{ H} NMR δ 15.4 (d, J P-C ) 3.9
Hz), 16.8, 20.9, 21.8 (d, J P-C ) 7.8 Hz, 22.2 (d, J P-C ) 7.7 Hz),
7.7 (d, J P-C ) 9.7 Hz), 30.7 (d, J P-C ) 15.7 Hz), 129.0 (d, J P-C
7.1 Hz), 129.8 (d, J P-C ) 6.8 Hz), 139.9, 141.4 (d, J P-C ) 9.6
Hz), 141.9 (d, J P-C ) 8.1 Hz), 195.6 (d, J P-C ) 8.1 Hz), 196.4
d, J P-C ) 8.1 Hz), 197.3 (d, J P-C ) 7.8 Hz), 198.1 (d, J P-C
8.4 Hz). Anal. Calcd for C18 PW: C, 40.78; H, 3.61.
Found: C, 40.75; H, 3.87.
85%): P NMR (CDCl
J
J
3
) δ -155.27 (dd, 1 P, J P-P ) 27.4 Hz,
P-W ) 241.5 Hz, P(CHMe)
2
), 22.36 (dd, 1 P, J P-P ) 27.4 Hz,
1
2
)
3 3
P-W ) 236.5 Hz, Ph P); H NMR (CDCl ) δ 0.86 (m, 1 H),
1.01-1.17 (m, 6 H), 1.53 (s, 1 H), 2.24 (s, 3 H), 2.29 (s, 3 H),
2.38 (s, 3 H), 6.77 (d, 2 H, J P-H ) 13.2 Hz), 7.32-7.36 (m, 9
H), 7.40-7.47 (m, 6 H); 13C{ H} NMR (CDCl
1
) δ 15.5 (d, J P-C
(
2
)
3
H
19
O
5
) 3.4 Hz), 16.4, 21.0, 22.0 (d, J P-C ) 7.5 Hz), 22.6 (d, J P-C
6.4 Hz), 29.4 (d, J P-C ) 8.9 Hz), 30.8 (d, J P-C ) 19.3 Hz), 128.2
)
(
1
9
d, J P-C ) 9.2 Hz), 128.5 (m) 129.5 (m), 129.7, 133.5 (d, J P-C
)
)
(
2 5
2R,3R)-(-)-MesP (CHMe) W(CO) (21). The same pro-
1.78 Hz), 136.4 (d, J P-C ) 35.6 Hz), 138.9, 141.2 (d, J P-C
cedure and same amounts of materials were used for the
.9 Hz), 142.4 (d, J P-C ) 7.4 Hz), 202.0 (m), 203.5 (m). Anal.
preparation of 21 from 4. Pure 21 (0.20 g, 74%) was obtained
3
1
35 34 4 2
Calcd for C H O P W: C, 54.99; H, 4.48. Found: C, 54.32;
as a pale yellow oil: P NMR δ -156.16 (J P-W ) 252.4 Hz);
1
H, 3.96.
H NMR δ 0.69-0.75 (m, 1 H), 0.80 (dd, 3 H, J P-H ) 13.4 Hz,
W(CO)
4
(P P h
3
2
)[(2R,3R)-(-)-MesP (CHMe) ] (24). The same
J
H-H ) 6.4 Hz), 0.99-1.10 (m, 1 H), 1.18 (dd, 3 H, J P-H ) 18.0
experimental procedure was followed as in the synthesis of
Hz, J H-H ) 6.7 Hz), 1.96 (s, 3 H), 2.31 (s, 3 H), 2.40 (s, 3 H),
1
3
1
22. A solution of W(CO) (PPh ) (0.3 g, 0.51 mmol) in 200 mL
6
1
2
)
1
.54 (d, 1 H, J P-H ) 2.6 Hz), 6.58 (s, 1 H); C{ H} NMR δ
5.4 (d, J P-C ) 3.8 Hz), 16.8, 20.9, 21.8 (d, J P-C ) 8.0 Hz),
2.2 (d, J P-C ) 7.8 Hz), 27.7 (d, J P-C ) 9.9 Hz), 30.7 (d, J P-C
5
3
of THF was used to prepare W(CO)
MesP(CHMe) (4) (0.11 g, 0.53 mmol) was reacted with the
freshly prepared W(CO) (PPh )(THF) in THF. Product was
extracted with 150 mL of hexane and chromatographed on
silica gel with hexane/ether (9:1) eluent. Pure W(CO) (PPh )-
] (24) (0.28 g, 72%) was obtained.
4 3
(PPh )(THF). (2R,3R)-
2
15.7 Hz), 129.0 (d, J P-C ) 7.1 Hz), 129.8 (d, J P-C ) 6.8 Hz),
39.8, 141.4 (d, J P-C ) 9.2 Hz), 141.9 (d, J P-C ) 7.9 Hz), 195.6
d, J P-C ) 8.1 Hz), 196.4 (d, J P-C ) 8.2 Hz), 197.3 (d, J P-C
4
3
(
8
)
4
3
[
(2R,3R)-(-)-MesP(CHMe)
2
19 5
.0 Hz), 198.1 (d, J P-C ) 28.0 Hz). Anal. Calcd for C18H O -
The material was recrystallized from a mixture of pentane and
PW: C, 40.78; H, 3.61. Found: C, 41.04; H, 3.90.
1
7
ether (1:1) at -5 to -10 °C giving X-ray quality light yellow
W(CO)
5
P P h
3
.
The procedure employed for the synthesis
(3.0 g, 8.53 mmol)
3
1
crystals: P NMR (CDCl ) δ -155.28 (dd, 1 P, J P-P ) 27.4
3
of 17 was followed with a solution of W(CO)
6
Hz, J P-W ) 240.8 Hz, P(CHMe)
2
), 22.36 (dd, 1 P, J P-P ) 27.4
P); H NMR (CDCl ) δ 0.87 (m, 1 H),
.02-1.17 (m, 6 H), 1.55-1.62 (m, 1 H), 2.24 (s, 3 H), 2.30 (s,
H), 2.38 (s, 3 H), 6.77 (d, 2 H, J P-H ) 13.1 Hz), 7.33-7.35
in 250 mL of THF. PPh
freshly prepared W(CO)
3
(2.3 g, 8.78 mmol) was reacted with
THF. After the reaction was com-
1
Hz, J P-W ) 238.0 Hz, Ph
3
3
5
1
3
(
plete, solvent was removed under vacuo, and the remaining
material was mixed with 200 mL of hexane and filtered to
remove the dark residue. After evaporation of the hexane from
the filtrate, the residue was recrystallized from a mixture of
m, 9 H), 7.41-7.48 (m, 6 H); 13C{ H} NMR (CDCl
) δ 15.5 (d,
1
3
J
J
P-C ) 3.1 Hz), 16.4, 21.0, 22.0 (d, J P-C ) 7.8 Hz), 22.6 (d,
P-C ) 6.7 Hz), 29.5 (d, J P-C ) 9.1 Hz), 30.8 (d, J P-C ) 18.1
hexane and ether (8:2) at -5 to -10 °C. Then 0.6 g of W(CO)
was recovered as white needles, and light yellow crystals of
W(CO) PPh (3.3 g, 82.5%) were obtained. Column chroma-
tography on silica gel can also be used to purify W(CO) PPh
if there is large amount of unreacted W(CO) present.
W(CO) (P P h )[(2S,3R)-m eso-MesP (CHMe) ] (22). In a
typical experiment a solution of W(CO) (PPh ) (0.2 g, 0.34
6
Hz), 128.2 (d, J P-C ) 9.2 Hz), 128.5 (m), 129.5 (m), 129.7, 133.5
(
J
d, J P-C ) 12.0 Hz), 136.4 (d, J P-C ) 37.1 Hz), 138.9, 141.2 (d,
5
3
P-C ) 9.7 Hz), 142.4 (d, J P-C ) 7.2 Hz), 201.8 (m), 203.5-
04.0 (m). Anal. Calcd for C35 W: C, 54.99; H, 4.48.
5
3
,
2
34 4 2
H O P
6
Found: C, 54.92; H, 4.17.
4
3
2
5
3
Ack n ow led gm en t. This work received finanical
support from the National Science Foundation Grant
CHE-9108130. We thank Professor J ohn R. Bleeke, Dr.
Alicia Beatty, and Dr. Thomas A. Straw for helpful
discussions. High-resolution and chemical ionization
mass spectra were provided by the Washington Uni-
versity Mass Spectrometry Resource. X.L. thanks Wash-
ington University for a University Fellowship.
mmol) in 120 mL of THF was placed in a Pyrex photolysis
tube (o.d. ) 4.5 cm, length ) 22 cm) with a magnetic stirring
bar, a nitrogen inlet to the bottom of the tube, and a nitrogen
outlet on the top. With stirring and nitrogen bubbling through
the reaction solution, the mixture was irradiated for 3 h with
a medium-pressure mercury lamp. The reaction was conve-
niently monitored by TLC (silica gel) with a mixture of pentane
and ether (9:1) as eluent. meso-anti-cis-MesP(CHMe) (5) (0.07
2
g, 0.34 mmol) was placed in a 250 mL flask equipped with a
rubber septum and a magnetic stirring bar. The freshly
Su p p or tin g In for m a tion Ava ila ble: 1H and 13C NMR
4 3
prepared yellow-orange THF solution of W(CO) (PPh )(THF)
peak assignments, IR absorptions, and MS fragmentation
patterns. Data acquisition details for X-ray structure deter-
minations and ORTEP drawings for 22, 23, and 24 (9 pages).
This material is contained in libraries on microfiche, im-
mediately follows this article in the microfilm version of the
journal, and can be ordered from the ACS; see any current
masthead page for ordering information. The author has
deposited atomic coordinates for structures 22, 23, and 24 with
the Cambridge Crystallographic Data Centre. The coordinates
can be obtained, on request, from the Director, Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge,
CB2 1EZ, U.K.
was transfered to the reaction flask with a double needle with
stirring. After a further 5 h with stirring, the mixture turned
from orange to light yellow or nearly colorless, and TLC
analysis suggested that the reaction was complete. Solvent
was removed under vacuo, and the remaining material was
mixed with 150 mL of hexane and filtered to remove the dark
residue. After evaporation of the hexane from the filtrate, the
residue was chromatographed on silica gel with hexane/ether
(
(
9:1) eluent, yielding W(CO)
22) (0.20 g, 77%) of high purity. This was recrystallized from
a mixture of pentane and ether (1:1) at -5 to -10 °C. X-ray
4 3 2
(PPh )[(2S,3R)-meso-MesP(CHMe) ]
3
1
quality light yellow crystals of 22 were obtained: P NMR δ
169.18 (dd, 1 P, J P-P ) 24.4 Hz, J P-W ) 240.8 Hz, P(CHMe) ),
-
2
J O9608533